diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/kernel/cpu/cyrix.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/i386/kernel/cpu/cyrix.c')
-rw-r--r-- | arch/i386/kernel/cpu/cyrix.c | 439 |
1 files changed, 439 insertions, 0 deletions
diff --git a/arch/i386/kernel/cpu/cyrix.c b/arch/i386/kernel/cpu/cyrix.c new file mode 100644 index 000000000000..ba4b01138c8f --- /dev/null +++ b/arch/i386/kernel/cpu/cyrix.c @@ -0,0 +1,439 @@ +#include <linux/init.h> +#include <linux/bitops.h> +#include <linux/delay.h> +#include <linux/pci.h> +#include <asm/dma.h> +#include <asm/io.h> +#include <asm/processor.h> +#include <asm/timer.h> + +#include "cpu.h" + +/* + * Read NSC/Cyrix DEVID registers (DIR) to get more detailed info. about the CPU + */ +static void __init do_cyrix_devid(unsigned char *dir0, unsigned char *dir1) +{ + unsigned char ccr2, ccr3; + unsigned long flags; + + /* we test for DEVID by checking whether CCR3 is writable */ + local_irq_save(flags); + ccr3 = getCx86(CX86_CCR3); + setCx86(CX86_CCR3, ccr3 ^ 0x80); + getCx86(0xc0); /* dummy to change bus */ + + if (getCx86(CX86_CCR3) == ccr3) { /* no DEVID regs. */ + ccr2 = getCx86(CX86_CCR2); + setCx86(CX86_CCR2, ccr2 ^ 0x04); + getCx86(0xc0); /* dummy */ + + if (getCx86(CX86_CCR2) == ccr2) /* old Cx486SLC/DLC */ + *dir0 = 0xfd; + else { /* Cx486S A step */ + setCx86(CX86_CCR2, ccr2); + *dir0 = 0xfe; + } + } + else { + setCx86(CX86_CCR3, ccr3); /* restore CCR3 */ + + /* read DIR0 and DIR1 CPU registers */ + *dir0 = getCx86(CX86_DIR0); + *dir1 = getCx86(CX86_DIR1); + } + local_irq_restore(flags); +} + +/* + * Cx86_dir0_msb is a HACK needed by check_cx686_cpuid/slop in bugs.h in + * order to identify the Cyrix CPU model after we're out of setup.c + * + * Actually since bugs.h doesn't even reference this perhaps someone should + * fix the documentation ??? + */ +static unsigned char Cx86_dir0_msb __initdata = 0; + +static char Cx86_model[][9] __initdata = { + "Cx486", "Cx486", "5x86 ", "6x86", "MediaGX ", "6x86MX ", + "M II ", "Unknown" +}; +static char Cx486_name[][5] __initdata = { + "SLC", "DLC", "SLC2", "DLC2", "SRx", "DRx", + "SRx2", "DRx2" +}; +static char Cx486S_name[][4] __initdata = { + "S", "S2", "Se", "S2e" +}; +static char Cx486D_name[][4] __initdata = { + "DX", "DX2", "?", "?", "?", "DX4" +}; +static char Cx86_cb[] __initdata = "?.5x Core/Bus Clock"; +static char cyrix_model_mult1[] __initdata = "12??43"; +static char cyrix_model_mult2[] __initdata = "12233445"; + +/* + * Reset the slow-loop (SLOP) bit on the 686(L) which is set by some old + * BIOSes for compatibility with DOS games. This makes the udelay loop + * work correctly, and improves performance. + * + * FIXME: our newer udelay uses the tsc. We don't need to frob with SLOP + */ + +extern void calibrate_delay(void) __init; + +static void __init check_cx686_slop(struct cpuinfo_x86 *c) +{ + unsigned long flags; + + if (Cx86_dir0_msb == 3) { + unsigned char ccr3, ccr5; + + local_irq_save(flags); + ccr3 = getCx86(CX86_CCR3); + setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */ + ccr5 = getCx86(CX86_CCR5); + if (ccr5 & 2) + setCx86(CX86_CCR5, ccr5 & 0xfd); /* reset SLOP */ + setCx86(CX86_CCR3, ccr3); /* disable MAPEN */ + local_irq_restore(flags); + + if (ccr5 & 2) { /* possible wrong calibration done */ + printk(KERN_INFO "Recalibrating delay loop with SLOP bit reset\n"); + calibrate_delay(); + c->loops_per_jiffy = loops_per_jiffy; + } + } +} + + +static void __init set_cx86_reorder(void) +{ + u8 ccr3; + + printk(KERN_INFO "Enable Memory access reorder on Cyrix/NSC processor.\n"); + ccr3 = getCx86(CX86_CCR3); + setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */ + + /* Load/Store Serialize to mem access disable (=reorder it) */ + setCx86(CX86_PCR0, getCx86(CX86_PCR0) & ~0x80); + /* set load/store serialize from 1GB to 4GB */ + ccr3 |= 0xe0; + setCx86(CX86_CCR3, ccr3); +} + +static void __init set_cx86_memwb(void) +{ + u32 cr0; + + printk(KERN_INFO "Enable Memory-Write-back mode on Cyrix/NSC processor.\n"); + + /* CCR2 bit 2: unlock NW bit */ + setCx86(CX86_CCR2, getCx86(CX86_CCR2) & ~0x04); + /* set 'Not Write-through' */ + cr0 = 0x20000000; + __asm__("movl %%cr0,%%eax\n\t" + "orl %0,%%eax\n\t" + "movl %%eax,%%cr0\n" + : : "r" (cr0) + :"ax"); + /* CCR2 bit 2: lock NW bit and set WT1 */ + setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x14 ); +} + +static void __init set_cx86_inc(void) +{ + unsigned char ccr3; + + printk(KERN_INFO "Enable Incrementor on Cyrix/NSC processor.\n"); + + ccr3 = getCx86(CX86_CCR3); + setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */ + /* PCR1 -- Performance Control */ + /* Incrementor on, whatever that is */ + setCx86(CX86_PCR1, getCx86(CX86_PCR1) | 0x02); + /* PCR0 -- Performance Control */ + /* Incrementor Margin 10 */ + setCx86(CX86_PCR0, getCx86(CX86_PCR0) | 0x04); + setCx86(CX86_CCR3, ccr3); /* disable MAPEN */ +} + +/* + * Configure later MediaGX and/or Geode processor. + */ + +static void __init geode_configure(void) +{ + unsigned long flags; + u8 ccr3, ccr4; + local_irq_save(flags); + + /* Suspend on halt power saving and enable #SUSP pin */ + setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88); + + ccr3 = getCx86(CX86_CCR3); + setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* Enable */ + + ccr4 = getCx86(CX86_CCR4); + ccr4 |= 0x38; /* FPU fast, DTE cache, Mem bypass */ + + setCx86(CX86_CCR3, ccr3); + + set_cx86_memwb(); + set_cx86_reorder(); + set_cx86_inc(); + + local_irq_restore(flags); +} + + +#ifdef CONFIG_PCI +static struct pci_device_id cyrix_55x0[] = { + { PCI_DEVICE(PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5510) }, + { PCI_DEVICE(PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5520) }, + { }, +}; +#endif + +static void __init init_cyrix(struct cpuinfo_x86 *c) +{ + unsigned char dir0, dir0_msn, dir0_lsn, dir1 = 0; + char *buf = c->x86_model_id; + const char *p = NULL; + + /* Bit 31 in normal CPUID used for nonstandard 3DNow ID; + 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway */ + clear_bit(0*32+31, c->x86_capability); + + /* Cyrix used bit 24 in extended (AMD) CPUID for Cyrix MMX extensions */ + if ( test_bit(1*32+24, c->x86_capability) ) { + clear_bit(1*32+24, c->x86_capability); + set_bit(X86_FEATURE_CXMMX, c->x86_capability); + } + + do_cyrix_devid(&dir0, &dir1); + + check_cx686_slop(c); + + Cx86_dir0_msb = dir0_msn = dir0 >> 4; /* identifies CPU "family" */ + dir0_lsn = dir0 & 0xf; /* model or clock multiplier */ + + /* common case step number/rev -- exceptions handled below */ + c->x86_model = (dir1 >> 4) + 1; + c->x86_mask = dir1 & 0xf; + + /* Now cook; the original recipe is by Channing Corn, from Cyrix. + * We do the same thing for each generation: we work out + * the model, multiplier and stepping. Black magic included, + * to make the silicon step/rev numbers match the printed ones. + */ + + switch (dir0_msn) { + unsigned char tmp; + + case 0: /* Cx486SLC/DLC/SRx/DRx */ + p = Cx486_name[dir0_lsn & 7]; + break; + + case 1: /* Cx486S/DX/DX2/DX4 */ + p = (dir0_lsn & 8) ? Cx486D_name[dir0_lsn & 5] + : Cx486S_name[dir0_lsn & 3]; + break; + + case 2: /* 5x86 */ + Cx86_cb[2] = cyrix_model_mult1[dir0_lsn & 5]; + p = Cx86_cb+2; + break; + + case 3: /* 6x86/6x86L */ + Cx86_cb[1] = ' '; + Cx86_cb[2] = cyrix_model_mult1[dir0_lsn & 5]; + if (dir1 > 0x21) { /* 686L */ + Cx86_cb[0] = 'L'; + p = Cx86_cb; + (c->x86_model)++; + } else /* 686 */ + p = Cx86_cb+1; + /* Emulate MTRRs using Cyrix's ARRs. */ + set_bit(X86_FEATURE_CYRIX_ARR, c->x86_capability); + /* 6x86's contain this bug */ + c->coma_bug = 1; + break; + + case 4: /* MediaGX/GXm or Geode GXM/GXLV/GX1 */ +#ifdef CONFIG_PCI + /* It isn't really a PCI quirk directly, but the cure is the + same. The MediaGX has deep magic SMM stuff that handles the + SB emulation. It thows away the fifo on disable_dma() which + is wrong and ruins the audio. + + Bug2: VSA1 has a wrap bug so that using maximum sized DMA + causes bad things. According to NatSemi VSA2 has another + bug to do with 'hlt'. I've not seen any boards using VSA2 + and X doesn't seem to support it either so who cares 8). + VSA1 we work around however. + */ + + printk(KERN_INFO "Working around Cyrix MediaGX virtual DMA bugs.\n"); + isa_dma_bridge_buggy = 2; +#endif + c->x86_cache_size=16; /* Yep 16K integrated cache thats it */ + + /* + * The 5510/5520 companion chips have a funky PIT. + */ + if (pci_dev_present(cyrix_55x0)) + pit_latch_buggy = 1; + + /* GXm supports extended cpuid levels 'ala' AMD */ + if (c->cpuid_level == 2) { + /* Enable cxMMX extensions (GX1 Datasheet 54) */ + setCx86(CX86_CCR7, getCx86(CX86_CCR7)|1); + + /* GXlv/GXm/GX1 */ + if((dir1 >= 0x50 && dir1 <= 0x54) || dir1 >= 0x63) + geode_configure(); + get_model_name(c); /* get CPU marketing name */ + return; + } + else { /* MediaGX */ + Cx86_cb[2] = (dir0_lsn & 1) ? '3' : '4'; + p = Cx86_cb+2; + c->x86_model = (dir1 & 0x20) ? 1 : 2; + } + break; + + case 5: /* 6x86MX/M II */ + if (dir1 > 7) + { + dir0_msn++; /* M II */ + /* Enable MMX extensions (App note 108) */ + setCx86(CX86_CCR7, getCx86(CX86_CCR7)|1); + } + else + { + c->coma_bug = 1; /* 6x86MX, it has the bug. */ + } + tmp = (!(dir0_lsn & 7) || dir0_lsn & 1) ? 2 : 0; + Cx86_cb[tmp] = cyrix_model_mult2[dir0_lsn & 7]; + p = Cx86_cb+tmp; + if (((dir1 & 0x0f) > 4) || ((dir1 & 0xf0) == 0x20)) + (c->x86_model)++; + /* Emulate MTRRs using Cyrix's ARRs. */ + set_bit(X86_FEATURE_CYRIX_ARR, c->x86_capability); + break; + + case 0xf: /* Cyrix 486 without DEVID registers */ + switch (dir0_lsn) { + case 0xd: /* either a 486SLC or DLC w/o DEVID */ + dir0_msn = 0; + p = Cx486_name[(c->hard_math) ? 1 : 0]; + break; + + case 0xe: /* a 486S A step */ + dir0_msn = 0; + p = Cx486S_name[0]; + break; + } + break; + + default: /* unknown (shouldn't happen, we know everyone ;-) */ + dir0_msn = 7; + break; + } + strcpy(buf, Cx86_model[dir0_msn & 7]); + if (p) strcat(buf, p); + return; +} + +/* + * Cyrix CPUs without cpuid or with cpuid not yet enabled can be detected + * by the fact that they preserve the flags across the division of 5/2. + * PII and PPro exhibit this behavior too, but they have cpuid available. + */ + +/* + * Perform the Cyrix 5/2 test. A Cyrix won't change + * the flags, while other 486 chips will. + */ +static inline int test_cyrix_52div(void) +{ + unsigned int test; + + __asm__ __volatile__( + "sahf\n\t" /* clear flags (%eax = 0x0005) */ + "div %b2\n\t" /* divide 5 by 2 */ + "lahf" /* store flags into %ah */ + : "=a" (test) + : "0" (5), "q" (2) + : "cc"); + + /* AH is 0x02 on Cyrix after the divide.. */ + return (unsigned char) (test >> 8) == 0x02; +} + +static void cyrix_identify(struct cpuinfo_x86 * c) +{ + /* Detect Cyrix with disabled CPUID */ + if ( c->x86 == 4 && test_cyrix_52div() ) { + unsigned char dir0, dir1; + + strcpy(c->x86_vendor_id, "CyrixInstead"); + c->x86_vendor = X86_VENDOR_CYRIX; + + /* Actually enable cpuid on the older cyrix */ + + /* Retrieve CPU revisions */ + + do_cyrix_devid(&dir0, &dir1); + + dir0>>=4; + + /* Check it is an affected model */ + + if (dir0 == 5 || dir0 == 3) + { + unsigned char ccr3, ccr4; + unsigned long flags; + printk(KERN_INFO "Enabling CPUID on Cyrix processor.\n"); + local_irq_save(flags); + ccr3 = getCx86(CX86_CCR3); + setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */ + ccr4 = getCx86(CX86_CCR4); + setCx86(CX86_CCR4, ccr4 | 0x80); /* enable cpuid */ + setCx86(CX86_CCR3, ccr3); /* disable MAPEN */ + local_irq_restore(flags); + } + } + generic_identify(c); +} + +static struct cpu_dev cyrix_cpu_dev __initdata = { + .c_vendor = "Cyrix", + .c_ident = { "CyrixInstead" }, + .c_init = init_cyrix, + .c_identify = cyrix_identify, +}; + +int __init cyrix_init_cpu(void) +{ + cpu_devs[X86_VENDOR_CYRIX] = &cyrix_cpu_dev; + return 0; +} + +//early_arch_initcall(cyrix_init_cpu); + +static struct cpu_dev nsc_cpu_dev __initdata = { + .c_vendor = "NSC", + .c_ident = { "Geode by NSC" }, + .c_init = init_cyrix, + .c_identify = generic_identify, +}; + +int __init nsc_init_cpu(void) +{ + cpu_devs[X86_VENDOR_NSC] = &nsc_cpu_dev; + return 0; +} + +//early_arch_initcall(nsc_init_cpu); |